import java.util.concurrent.locks.ReentrantLock;

public class Demo3 {
    private static int count;
    public static void main(String[] args) throws InterruptedException {
        ReentrantLock locker=new ReentrantLock();
        Thread t1=new Thread(()->{
            locker.lock();
            for (int i = 0; i < 50000; i++) {
                count++;
            }
            locker.unlock();
        });
        Thread t2=new Thread(()->{
            for (int i = 0; i < 50000; i++) {
                locker.lock();
                count++;
            }
            locker.unlock();
        });

        t1.start();
        t2.start();
        t1.join();
        t2.join();
        System.out.println("count="+count);
    }
}
